Article Transport Apparatus

ABSTRACT

Provided is an article transport apparatus which can transfer an article to a transfer target portion at a low height. A movable member having a support portion includes a transfer mechanism for moving an article between the support portion and a transfer target portion. The transfer mechanism includes an interlocking portion capable of being interlocked with an article along the front-and-back direction, a first guide portion for guiding the interlocking portion along the front-and-back direction, and a second actuator for moving the interlocking portion along the front-and-back direction. The transfer mechanism moves an article between the support portion and the transfer target portion by moving the interlocking portion along the front-and-back direction. The first guide portion and the second actuator are located higher than an article supported by the support portion.

TECHNICAL FIELD

The present invention relates to an article transport apparatuscomprising a movable member having a support portion for supporting anarticle from below, and first actuators for moving the movable member.

BACKGROUND ART

A conventional example of such an article transport apparatus isdescribed in JP H01-187112 (Patent Document 1). In the article transportapparatus of Patent Document 1, an article is moved between a supportportion and a transfer target portion by a transfer mechanism after amovable member is moved to a target stop location by the actuating powerof a first actuator. To describe the transfer mechanism further, thetransfer mechanism has hooks which engage an article along afront-and-back direction, guide rails which guide the hooks along thefront-and-back direction, and a reversible motor for moving the hooksalong the front-and-back direction, and is configured to move an articlebetween the support portion and a transfer target portion by moving thehooks along the front-and-back direction with the reversible motor.

PRIOR ART DOCUMENTS Patent Documents

Patent Document 1: JP H01-187112

SUMMARY OF THE INVENTION Problems to be Solved by the Invention

In the article transport apparatus described above, the guide rails arelocated below the support portion, and the reversible motor is solocated that it projects downward to a location below the supportportion. In other words, the guide rails and the reversible motor arelocated below the support portion. Thus, a portion of a movable memberthat is located below the support portion is large in size along avertical direction; thus, when lowering the movable member, it was notpossible to lower the article supported by the support portion to asufficiently low height. Thus, it was difficult to provide a transfertarget portion at a low location.

The article transport apparatus is desired which can transfer an articleto a transfer target portions at a low height. Means for Solving theProblems

An article transport apparatus in accordance with the present disclosurecomprises: a movable member having a support portion for supporting anarticle from below; and first actuators for moving the movable member,characterized in that the movable member includes a transfer mechanismfor moving an article between the support portion and a transfer targetportion, to or from which the article is to be transferred, with thesupport portion and transfer target portion in alignment with eachother, wherein, with a target stop location being a location at whichthe movable member is stopped when moving an article between the supportportion and the transfer target portion with the transfer mechanism,with a front-and-back direction being a direction along which themovable member and the transfer target portion are spaced apart fromeach other as seen along the vertical direction when the movable memberis located at the target stop location, and with a lateral directionbeing a direction that crosses the front-and-back direction as seenalong the vertical direction, the transfer mechanism includes aninterlocking portion capable of being interlocked with an article alongthe front-and-back direction, a first guide portion for guiding theinterlocking portion along the front-and-back direction, and a secondactuator for moving the interlocking portion along the front-and-backdirection, wherein the transfer mechanism moves an article between thesupport portion and the transfer target portion by moving theinterlocking portion along the front-and-back direction by means of thesecond actuator with the movable member located at the target stoplocation, and wherein the first guide portion and the second actuatorare so located to be higher than an article supported by the supportportion.

With such an arrangement, an article, with which the interlockingportion is interlocked, is moved between the support portion and thetransfer target portion by moving the interlocking portion along thefront-and-back direction by means of the second actuator with themovable member located at the target stop location.

And the first guide portion for guiding the interlocking portion alongthe front-and-back direction and the second actuator for moving theinterlocking portion along the front-and-back direction are locatedhigher than an article supported by the support portion. Thus, it is notnecessary to locate either the first guide portion or the secondactuator lower than the support portion. Thus a portion of the movablemember that is located lower than the support portion can be madesmaller in size along the vertical direction. Accordingly, the movablemember can be arranged, or can be lowered further, such that the supportportion can be located at a lower height, compared with a case where thefirst guide portion and the second actuator are located lower than thesupport portion, which makes it possible to transfer an article to andfrom a transfer target portion at a low height.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a plan view of an article transport facility,

FIG. 2 is a perspective view of a storage rack as seen from a positionforward and above,

FIG. 3 is a perspective view of a server as seen from a positiondiagonally above,

FIG. 4 is a perspective view of the server seen from a positiondiagonally below,

FIG. 5 is a perspective view of a lock mechanism,

FIG. 6 is a side view of the lock mechanism,

FIG. 5 is a front view of the lock mechanism,

FIG. 8 is a plan view of a storage portion,

FIG. 9 is a side view of a stacker crane,

FIG. 10 is a side view of a vertically movable member,

FIG. 11 is a front view of a vertically movable member,

FIG. 12 is a plan view of an article transfer device,

FIG. 13 is a control block diagram,

FIG. 14 is a drawing showing how the article transfer device functionswhen storing or retrieving two servers,

FIG. 15 is a drawing showing how the article transfer device functionswhen storing or retrieving two servers,

FIG. 16 is a drawing showing how the article transfer device functionswhen storing or retrieving two servers,

FIG. 17 is a drawing showing how the article transfer device functionswhen storing or retrieving two servers,

FIG. 18 is a drawing showing how the article transfer device functionswhen storing or retrieving one server,

FIG. 19 is a drawing showing how the article transfer device functionswhen storing or retrieving one server,

FIG. 20 is a drawing showing how the article transfer device functionswhen storing or retrieving one server,

FIG. 21 is a drawing showing how the article transfer device functionswhen storing or retrieving one server,

FIG. 22 is a front view of an interlocking portion and an interlockedportion in the alternative embodiment 6,

FIG. 23 is a plan view showing the state in which the servers are at anangle with respect to the transfer device in the alternative embodiment6,

FIG. 24 is a drawing showing how the article transfer device functionswhen storing or retrieving two dummy articles in the alternativeembodiment 7,

FIG. 25 is a drawing showing how the article transfer device functionswhen storing or retrieving one dummy article and one server in thealternative embodiment 7, and

FIG. 26 is a drawing showing how the article transfer device functionswhen storing or retrieving one dummy article in the alternativeembodiment 7.

MODES FOR CARRYING OUT THE INVENTION

Embodiments of an article transport facility provided with an articletransport apparatus in accordance with the present invention aredescribed with reference to the drawings.

As shown in FIG. 1, an article transport facility includes a stackercrane 2 as an article transport apparatus for transporting an article 1,storage racks 4 in which storage portions 3 for storing articles 1 arearranged one above another along the vertical direction Y, and acarry-out conveyor 5, and a carry-in conveyor 6. A plurality of storageracks 4 are arranged one adjacent to another along a lateral directionX. And the stacker crane 2 moves along the storage racks 4 arranged oneadjacent to another and along the lateral direction X.

Note that, in the following description, the lateral direction X is adirection along which the stacker crane 2 travels as seen along thevertical direction Y, and the front-and-back direction Z is a directionperpendicular to the lateral direction X as seen along the verticaldirection Y. In addition, as shown in FIG. 2, along the front-and-backdirection Z, the back direction Z1 is the direction in which the storagerack 4 exists with respect to the travel path, and the front directionZ2 is the direction, along the front-and-back direction Z, that isopposite from the back direction.

In the present embodiment, occupied storage racks 4 which already havearticles 1 stored in them are installed in the article transportfacility. And when a malfunction, etc., occurs in an article 1 stored ina storage rack 4 and it needs to be replaced, the article 1 to bereplaced is retrieved from the storage portion 3 and is transported tothe carry-out conveyor 5 by the stacker crane 2. And a new article 1carried in by the carry-in conveyor 6 is transported by the stackercrane 2 to the storage portion 3 (the storage portion 3 from which thearticle 1 being replaced was retrieved).

[Articles]

In the present embodiment, the servers 1 s, as articles 1, are stored inthe storage racks 4 and are transported by the stacker crane 2. Inaddition, in the article transport facility, as articles 1, there aredummy articles 1 d (see, for example, FIG. 18) whose shapes, as seenalong a vertical direction Y, are formed in the same shape as the shapeof the servers 1 s. Note that, in the present embodiment, although thereare cases where two servers 1 s are transported together by the stackercrane 2 as well as cases where a server 1 s and a dummy article 1 d aretransported together, the servers 1 s are stored in storage portions 3whereas no dummy articles 1 d are stored in storage portions 3.

The servers 1 s are described next. In the following description, thefront-and-back direction Z and the lateral direction X of a server 1 sare defined based on the attitude of the server 1 s when stored in astorage portion 3.

As shown in FIG. 2, each server 1 s is formed such that its width alongthe front-and-back direction Z is greater than the width along thelateral direction X, and each server 1 s is stored in a storage rack 4in an attitude in which its longer side extends along the front-and-backdirection.

As shown in FIGS. 3 and 4, a servers 1 s has a housing 8 and a substrate(not shown) on which CPU, memory, hard disks, etc. are mounted. Thehousing 8 is formed to have a bottom face portion 9 and wall portions 10arranged to extend vertically from the bottom face portion 9. Thehousing 8 is formed in a box shape whose upper area and back area areopen. The substrate is fixed on the bottom face portion 9.

The bottom face portion 9 consists of a back end portion 9 a provided ata location in the back direction Z1, and a front portion 9 b provided ata location in the front direction Z2 with respect to this back endportion 9 a.

The front portion 9 b is formed in a rectangular shape as seen along thevertical direction Y. The back end portion 9 a has a rectangle portionformed in a rectangular shape having a width along the lateral directionX that is narrower than the front portion 9 b, and a tapered portionwhich is located between this rectangle portion and the front portion 9b and whose width along the lateral direction X is gradually narrowertoward its back direction Z1 side end. With the back end portion 9 a soformed, the width of the article 1 along the lateral direction X is soformed to be gradually narrower toward the back direction Z1 side end.

Although a portion of the back end portion 9 a is formed in a taperedshape in the present embodiment, the entire back end portions 9 a mayhave a tapered shape.

As the wall portions 10, there are provided lateral wall portions 10 awhich are located at end portions along the lateral direction X andextend along the front-and-back direction, and a front wall portion 10 bwhich is located at a front direction Z2 side end portion and extendsalong the lateral direction X.

Each server 1 s is provided with bar-shaped first engaging portions 11and second engaging portions 12 both for positioning, a lock mechanism13 (see FIG. 5), and interlocked portions 16. As shown in FIG. 3, thefirst engaging portions 11 are located in the back direction Z1 side endportion of the article 1 such that they project upward from the bottomface portion 9. As shown in FIG. 4, the second engaging portions 12 arelocated in the front direction Z2 side end portion of each article 1such that they project downward from the bottom face portion 9. Theinterlocked portions 16 are located on the front face of the front wallportion 10 b of the article 1, and are generally formed in a shape of a“U” as seen along the vertical direction Y. The interlocked portions 16are so configured to allow an interlocking portion 37 of a transfermechanism 32 described below to be interlocked with the interlockedportions 16 by being inserted from above into the space between theinterlocked portions 16 and the front wall portion 10 b. In addition, aninterlocked portion 16 is located in a portion of the front wall portion10 b of the article 1 that is located to one side of a center along thelateral direction X and an interlocked portion 16 is located in aportion on the other side. An article 1 is provided with a pair ofinterlocked portions 16 that are so located to be spaced apart from eachother along the lateral direction X.

As shown in FIGS. 5 through 7, the lock mechanism 13 is located in thefront direction Z2 side end portion of the article 1.

The lock mechanism 13 consists of an engaging member 14 which consistsof a leaf spring, and a swing member 15 swingable about an axisextending along the front-and-back direction Z.

The engaging member 14 has a fixed portion 14 a fixed to the top surfaceof the bottom face portion 9, a contact portion 14 b which can beoperated to be moved upward by the swing member 15, and a third engagingportion 14 c which projects downward from a hole that extends throughthe bottom face portion 9 along the vertical direction Y. The swingmember 15 is connected to the front wall portion 10 b such that itsintermediate portion along a direction it extends is swingable about anaxis extending along the front-and-back direction Z. And one end portionof the swing member 15 along the direction it extends projects from ahole which extends through the front wall portion 10 b along thefront-and-back direction Z. The portion of the swing member 15 thatprojects from the front wall portion 10 b is configured as an operatedportion 15 a. This operated portion 15 a projects from a centralportion, along the lateral direction X, of the front wall portion 10 b.

As shown in FIGS. 5-7, when the operated portion 15 a is not operated oracted on, the lock mechanism 13 is in a locking state in which the thirdengaging portion 14 c projects downward from the bottom face portion 9.And in the lock mechanism 13, the other end portion of the swing member15 along the direction it extends pushes the contact portion 14 b upwardfrom the state shown in FIG. 7, as an operating portion 38 is moveddownward and presses the operated portion 15 a downward. This causes thelock mechanism 13 to be switched to a lock release state in which thethird engaging portion 14 c does not project downward from the bottomface portion 9. In addition, the lock mechanism 13 is switched from thelock release state to the locking state by the resilience of the leafsprings, as the operated portion 15 a is released from being pressed.

[Storage Racks]

Each storage rack 4 consists of rack forming body 17 and shelves 20. Therack forming body 17 consist of a base frame which is a framework formedby frame members, and flat and thin plate members. And a plurality ofstorage portions 3 arranged one above another along the verticaldirection Y are formed in a storage rack 4 by dividing the storage spaceformed in the rack forming body 17 into a plurality of spaces arrangedone above another along the vertical direction Y by means of a pluralityof shelves 20.

Incidentally, the storage portion 3 at the highest level is formedbetween a portion of the rack forming member 17 that covers the top ofthe storage space and the shelf 20 that is at the highest location amongthe plurality of shelves 20. In addition, the storage portion 3 at thelowest level is formed between a portion of the rack forming member 17that covers the bottom of the storage space and the shelf 20 that is atthe lowest location among the plurality of shelves 20.

As shown in FIG. 8, each of the plurality of storage portions 3 providedto a storage rack 4 includes a plurality of storage areas E that areadjacent to each other along the lateral direction X, and is configuredto be capable of storing a plurality of articles 1 with the articlesarranged adjacent each other along the lateral direction X.

More specifically, the distance between two side walls 17 a which coverboth lateral sides of the storage space in the rack forming member 17 isgreater, by about a few millimeters, than twice the lateral width of anarticle 1 (width of the front portion 9 b along the lateral directionX).

In addition, the distance, along the vertical direction Y, between twoshelves 20 that are adjacent to each other along the vertical directionY is greater, by a few millimeters, than a portion of an article 1 thathas the greatest vertical width. Each article 1 is stored with itsbottom surface supported from below by the top surface of a shelf 20.

Each of a plurality of storage portions 3 is capable of storing a pairof articles 2 in the pair of storage areas E that are adjacent to eachother along the lateral direction X with the articles arranged adjacentto each other along the lateral direction X. In addition, the pair ofside walls 17 a function as second guide members 24 for contacting thearticles 1 from lateral directions X to guide the articles 1 along thefront-and-back direction Z when moving the articles 1 with the transfermechanism 32 described below.

And the second guide members 24 are provided at locations in the backdirection Z1 (on the storage portion 3 side) with respect to guidemembers 33 provided to the vertically movable member 28 when thevertically movable member 28 is located at a target stop location. Andthe second guide members 24 are provided only on both outboard sidesalong the lateral direction X of a second article group which consistsof the two articles 1 stored in a storage portion 3.

Note that a target stop location of the vertically movable member 28 isa location at which the vertically movable member 28 is stopped whenmoving an article 1 between the support portion 31 and a storage area Eof a storage portion 3. In addition, when the vertically movable member28 is located at a target stop location, the vertically movable member28 and storage areas E are aligned with, and spaced apart from, eachother along the front-and-back direction Z.

First engaged portions 21 are provided in the back direction Z1 side endportion of a shelf 20. When an article 1 is stored in a storage area Eof a storage portion 3, the first engaging portions 11 of the article 1engage the first engaged portions 21. In addition, second engagedportions 22 are provided in the front direction Z2 side end portion ofthe shelf 20. When an article 1 is stored in a storage area E of astorage portion 3, the second engaging portions 12 of the article 1engage the second engaged portions 22.

Third engaged portions 23 are provided in the front direction Z2 sideend portion of the shelf 20. The third engaging portion 14 c of the lockmechanism 13 engages the third engaged portion 23 by switching the lockmechanism 13 of the article 1 to the locking state with the article 1stored in a storage area E of a storage portion 3.

Note that the portion of the rack forming member 17 that covers thebottom of the storage space is provided with the first engaged portions21, the second engaged portions 22, and the third engaged portions 23 aswith a shelf 20.

The storage racks 4 are installed on both sides, along thefront-and-back direction Z, of the travel path of the stacker crane 2.The storage areas E are located on the both sides, along thefront-and-back direction Z, of the movable member stopped at a targetstop location. The storage areas E correspond to transfer targetportions.

[Stacker Crane]

As shown in FIGS. 1, 9, and 10, the stacker crane 2 has a verticallymovable member 28 having a support portion 31 for supporting articles 1from below, a first motor M1 (see FIG. 13) as a travel actuator formoving the vertically movable member 28, and a second motor M2 (see FIG.13) as a vertical movement actuator.

To describe this further, the stacker crane 2 has a travel carriage 26as a travel portion which travels along the travel path, a supportcolumn 27 as a second guide portion arranged vertically on the travelcarriage 26, the vertically movable member 28 which is moved along thesupport column 27 and thus along the vertical direction Y, the firstmotor M1 for causing the travel carriage 26 to travel, and the secondmotor M2 for moving the vertically movable member 28 along the supportcolumn 27 and thus along the vertical direction Y. The verticallymovable member 28 is moved along the lateral direction X as a result ofthe fact that the travel carriage 26 travels under the actuating powerof the first motor M1. The vertically movable member 28 is moved alongthe vertical direction Y by the actuating power of the second motor M2.

Thus, the vertically movable member 28 is configured to be moved alongthe lateral direction X and the vertical direction Y by the actuatingpower of the first motor M1 and the second motor M2. This verticallymovable member 28 corresponds to the movable member which is moved alongthe vertical direction Y and the lateral direction X. In addition, thefirst motor M1 and the second motor M2 correspond to the first actuatorsfor moving the movable member.

The travel carriage 26 travels on a pair of guide rails 25 along thelateral direction X. The pair of guide rails 25 are so located that theyextend along the lateral direction X and are spaced apart from eachother along the front-and-back direction Z. The support column 27 isarranged vertically on the travel carriage 26 to guide the verticallymovable member 28 along the vertical direction Y.

As shown in FIGS. 10-12, the vertically movable member 28 includes asupport portion 31, a transfer mechanism 32, and the guide members 33.

The support portion 31 consists of two pairs of support members 31 awith the support members 31 a in each pair being spaced apart from eachother along the lateral direction X and with the two pairs being spaceapart from each other along the lateral direction X. Each pair ofsupport members 31 a is configured to support one article 1 from below.In other words, as a result of the support portion 31 consisting of twopairs of support members 31 a that are space apart from each other alongthe lateral direction X, it can support two articles 1 with the articles1 located adjacent to each other along the lateral direction X. Aplurality of articles 1 that are supported by this support portion 31are referred to as a first article group. In addition, two articles 1that are supported by a shelf 20 of a storage rack 4 are referred to asa second article group. Each of a first article group and a secondarticle groups consists of two articles 1 that are adjacent to eachother along the lateral direction X.

The transfer mechanism 32 moves an article 1 between the support portion31 and a transfer target portion, to or from which the article 1 is tobe transferred, with the support portion 31 and the transfer targetportion in alignment with, and spaced part from, each other along thefront-and-back direction Z. The transfer mechanism 32 has forkmechanisms 35 which can be projected and retracted along thefront-and-back direction Z, slide members 36 supported by primary forks35 a of the fork mechanisms 35 for movement along the front-and-backdirection Z, interlocking portions 37 supported by the slide members 36capable of being interlocked with articles 1 along the front-and-backdirection Z, and operating portions 38 supported by the slide members 36for switching the lock mechanisms 13 of the articles 1 from the lockingstate to the lock release state. In addition, the transfer mechanism 32has third motors M3 as the projecting and retracting actuators forprojecting and retracting the fork mechanisms 35, movement couplingmechanisms (not shown) which move the slide members 36 along thefront-and-back direction Z when the fork mechanisms 35 are projected andretracted, and fourth motors M4 for moving the interlocking portions 37and the operating portions 38 along the vertical direction Y by movingthe fork mechanisms 35 along the vertical direction Y with respect tothe support portion 31.

As such, the transfer mechanism 32 has the interlocking portions 37 andthe fork mechanisms 35. A fork mechanism 35 (more specifically, aprimary fork 35 a and a fork base portion 35 b) corresponds to the firstguide portion for guiding an interlocking portion 37 along thefront-and-back direction Z whereas a third motor M3 corresponds to thesecond actuator for moving an interlocking portion 37 along thefront-and-back direction Z. And the transfer mechanism 32 moves anarticle 1 between the support portion 31 and a transfer target portionby moving an interlocking portion 37 along the front-and-back directionZ with a third motor M3 with the vertically movable member 28 located ata target stop location. A interlocking portion 37 consists of a pair ofinterlocking members 37 a. The interlocking members 37 a of this pairare simultaneously interlocked with a pair of interlocked portions 16provided to an article 1. A interlocking portion 37 (each of theinterlocking members 37 a of a pair) is formed to be generally flat andthin which extends along the vertical direction Y and along thefront-and-back direction Z. The operating portion 38 is formed to begenerally flat and thin which extends along the vertical direction Y andalong the front-and-back direction Z., as is an interlocking portion 37.This operating portion 38 is provided between the pair of interlockingportions 37 along the lateral direction X.

Each primary fork 35 a is moved along the front-and-back direction Zwith respect to the fork base portion 35 b by the actuating power of thethird motor M3. This causes a fork mechanism 35 to be projected andretracted along the front-and-back direction Z. In addition, thearrangements are made such that, when the fork mechanism 35 is projectedand retracted, the slide member 36 is moved to the back direction Z1 endportion of the primary fork 35 a as the primary fork 35 a is projectedin the back direction Z1 and such that the slide member 36 is moved tothe front direction Z2 end portion of the primary fork 35 a as theprimary fork 35 a is retracted in the front direction Z2.

Each fork mechanism 35 is moved along the vertical direction Y withrespect to the support portion 31 by the actuating power of a fourthmotor M4. By this movement of the fork mechanism 35 along the verticaldirection Y, the interlocking portion 37 is moved to a first height atwhich the interlocking portion 37 is interlocked with the interlockedportions 16 of an article 1, and to a second height at which theinterlocking portion 37 is released from the interlocked portion 16 andis retracted upward from the interlocked portion 16. Note that a fourthmotor M4 corresponds to the third actuator for moving an interlockingportion 37 to the first height and to the second height.

The transfer mechanism 32 moves an article 1 between the support portion31 and a storage area E of a storage portion 3 as a result of theinterlocking portion 37 being moved along the front-and-back direction Zby the third motor M3, with the vertically movable member 28 at rest ata target stop location.

To describe this further, when moving an article 1 from a storage area Eof a storage portion 3 to the support portion 31, the transfer mechanism32 projects a fork mechanism 35 in the back direction Z1 from aretracted state with the vertically movable member 28 at rest at atarget stop location and with the interlocking portion 37 raised to thesecond height, to position the interlocking portion 37 between theinterlocked portions 16 and the front wall portion 10 b of the article 1along the front-and-back direction Z. Subsequently, the transfermechanism 32 lowers the fork mechanism 35 to lower the interlockingportion 37 to the first height to cause the interlocking portion 37 tobe interlocked with the article 1, then retracts the fork mechanism 35to the retracted state. By lowering the fork mechanism 35, the operatedportion 15 a is pushed downward by the operating portion 38, whichswitches the lock mechanism 13 from the locking state to the lockrelease state. Subsequently, the interlocking portion 37 is moved in thefront direction Z2 so that the interlocked portions 16 of the article 1is pulled by the interlocking portion 37, as a result of which thearticle 1 is moved in the back direction Z1. Thus, the article 1 ismoved from the storage area E of the storage portion 3 to the supportportion 31.

In addition, when moving an article 1 from the support portion 31 to astorage area E of a storage portion 3, the transfer mechanism 32projects the fork mechanism 35 in the back direction Z1 from theretracted state with the vertically movable member 28 at rest at atarget stop location and with the interlocking portion 37 interlockedwith the article 1 supported by the support portion 31. This causes theinterlocking portion 37 to push the front wall portion 10 b of thearticle 1 and causes the article 1 to be moved in the back direction Z1,which results in the article 1 being moved from the support portion 31to the storage area E of the storage portion 3. Subsequently, the forkmechanism 35 is raised to raise the interlocking portion 37 to thesecond height to release the interlocking portions 37 from the article1. Then the fork mechanism 35 is retracted to the retracted state.Raising the fork mechanism 35 releases the operated portion 15 a frombeing pushed downward by the operating portion 38, which switches thelock mechanism 13 from the lock release state to the locking state.

The transfer mechanism 32 has the same number of the sets (two sets inthe present embodiment) as the number (i.e., two in the presentembodiment) of articles 1 in a first article group with each setconsisting of a fork mechanism 35, a slide member 36, interlockingportion 37, and the operating portion 38. The transfer mechanism 32 hasa pair of interlocking portions 37 one for each of the two articles 1 inthe first article group.

The transfer mechanism 32 can move two articles 1 supported by thesupport portion 31 to storage areas E of a storage portion 3 at once bymoving the pair of interlocking portions 37 together by means of thethird motors M3. When moving two articles, that are adjacent to eachother along the lateral direction X, from the support portion 31 to thestorage areas E of a storage portion 3 with the transfer mechanism 32,the two articles 1 are guided so as not to deviate along the lateraldirection X by a pair of guide members 33.

In addition, the transfer mechanism 32 can move one of the two articles1 supported by the support portion 31 (i.e., only one of the articles 1of a first article group) to a storage area E of a storage portion 3 bymoving one of the interlocking portions 37 of a pair with a third motorM3. When moving one article 1 from the support portion 31, to a storagearea E of a storage portion 3 with the transfer mechanism 32, this onearticle being transferred 1 is guided so as not to deviate along thelateral direction X by a guide member 33 and another article 1 of thefirst article group.

To further describe the case where one article 1 is moved, when movingone of the two articles 1 supported by the support portion 31 (only oneof the articles 1 of a first article group) to a storage area E of astorage portion 3 as described above, a dummy article 1 d is supportedby the support portion 31 as the other article 1 in the first articlegroup. In short, in this case, the first article group consists of theserver 1 s which is the article to be transferred 1, and a dummy article1 d that is not to be transferred.

And with the second side being the side along the lateral direction X onwhich a dummy article 1 d exists with respect to the article to betransferred 1 and with the first side being the side opposite from thesecond side, when moving the article to be transferred 1 to a storagearea E of a storage portion 3 from the support portion 31 with thetransfer mechanism 32, the portion, on the first side along the lateraldirection X, of this article to be transferred 1 is guided by a guidemember 33 whereas the portion, on the second side along the lateraldirection X, of the article to be transferred 1 is guided by the dummyarticle 1d.

In addition, as described above, when moving one of the two articles 1supported by the support portion 31 (only one of the articles 1 of thefirst article group) to a storage area E of a storage portion 3, onearticle 1 in a second article group will be the article soon to betransferred 1 to the storage area E whereas the other article 2 of thesecond article group is the article 1 already stored in the storageportion 3.

And, with the second side being the side, along the lateral direction X,on which the article that has been already stored is located withrespect to the article 1 being transferred and with the first side beingthe side opposite from the second side, when moving an article 1, thatis to be transferred, from the support portion 31 to a storage area E ofa storage portion 3 with the transfer mechanism 32, the portion, on thefirst side along the lateral direction X, of this article beingtransferred 1 is guided by a side wall 17 a whereas the portion, on thesecond side along the lateral direction X, of this article to beingtransferred 1 is guided by the article 1 already stored in the storageportion 3.

The vertically movable member 28 includes a pair of guide members 33 forguiding the articles 1 along the front-and-back direction Z when thearticles 1 are moved by the transfer mechanism 32, and a fifth motor M5for changing the distance between the guide members 33 of the pair alongthe lateral direction X to a first distance, and to a second distancewhich is a distance along the lateral direction X that is greater thanthis first distance. The guide members 33 of the pair are provided onlyat one and the other side, along the lateral direction X, of the firstarticle group respectively. The guide members 33 of the pair are movedin opposite directions along the lateral direction X by the actuatingpower of the fifth motor M5 to change the distance between the guidemembers 33 of the pair along the lateral direction X, to the firstdistance which is slightly (about several millimeters) greater than thelateral width of a first article group and to the second distance whichis a distance along the lateral direction X that is larger than thisfirst distance. Note that the second distance can be either a distancebetween the guide members 33 of the pair after both of them are movedaway from each other (see FIG. 17) or, a distance between the guidemembers 33 of the pair after only one of them is moved away from theother (see FIG. 21). Note that the pair of guide members 33 correspondto the third guide portions for contacting articles 1 from the lateraldirection X to guide the articles 1 along the front-and-back direction Zwhen the transfer mechanism 32 moves articles 1.

The vertically movable member 28 includes a connecting portion 41, aswing portion 42, a swing mechanism 43, a sliding mechanism 44, and arotating mechanism 45.

A support column 27 is arranged vertically in one side end portion,along the lateral direction X, of the travel carriage 26. The connectingportion 41 is engaged with the support column 27 for movement withrespect thereto along the vertical direction Y at a location on oneside, along the lateral direction X, of the support column 27. Becausethe connecting portion 41 is engaged with the support column 27 at alocation on one side, along the lateral direction X, of the supportcolumn 27, the vertically movable member 28 is located to one side,along the lateral direction X, of the support column 27. The articletransfer device 30 including the support portion 31 is so located thatit does not overlap with the travel carriage 26 as seen along thevertical direction Y.

The swing portion 42 is generally formed in a shape of an “L” as seenalong the front-and-back direction Z. And the upper end of the swingportion 42 is connected to the connecting portion 41 such that the swingportion 42 can be swung about a swing axis that extends along thefront-and-back direction Z. In addition, the swing portion 42 supportsthe support portion 31, the transfer mechanism 32, and the guide members33 through the sliding mechanism 44 and the rotating mechanism 45.

The swing mechanism 43 is configured to swing the support portion 31,the transfer mechanism 32, and the guide members 33 together as a resultof the swing portion 42 being swung about the swing axis with respect tothe connecting portion 41 by the actuating power of the eighth motor M8.The support portion 31, the transfer mechanism 32, and the guide members33 are moved together by the swing mechanism 43, the sliding mechanism44, and the rotating mechanism 45. In the description below, the supportportion 31, the transfer mechanism 32, and the guide members 33, and anymembers that connect these to one another may be referred tocollectively as an article transfer device 30.

The rotating mechanism 45 is supported by the swing portion 42 to belocated lower than the swing portion 42, and supports the slidingmechanism 44 such that the sliding mechanism 44 can be rotated about arotation axis extending along the vertical direction Y. The slidingmechanism 44 supports the article transfer device 30 such that thearticle transfer device 30 can be moved along the lateral direction X.

The rotating mechanism 45 is configured to rotate the article transferdevice 30 supported by the sliding mechanism 44 about the rotation axisas a result of the sliding mechanism 44 being rotated about the rotationaxis with respect to the swing portion 42 by the actuating power of thesixth motor M6. Thus, by rotating the article transfer device 30 aboutthe rotation axis, the support portion 31, the transfer mechanism 32,and the guide members 33 are rotated together about the vertical axis.Note that the sixth motor M6 corresponds to the fourth actuator forrotating the transfer mechanism 32 through at least 180 degrees about anaxis extending along the vertical direction Y

The sliding mechanism 44 is configured to move the article transferdevice 30 along the lateral direction X with respect to the swingportion 42 by the actuating power of the seventh motor M7. Thus, bymoving the article transfer device 30 along the lateral direction X, thesupport portion 31, the transfer mechanism 32, and the guide members 33are moved together along the lateral direction X.

The support portion 31 is so located to be between the pair of guiderails 25 along the front-and-back direction Z as shown in FIG. 11, andis so located that the support portion 31 does not overlap with thetravel carriage 26 as seen along the vertical direction Y as shown inFIGS. 1 and 10.

In addition, the pair of guide members 33 are located, along thevertical direction Y, between the support portion 31 on the one hand andthe fork mechanism 35 and the third motor M3 on the other hand. Todescribe this further, the upper ends of the pair of guide members 33are located higher than the top surfaces of the support portion 31(i.e., surfaces on which articles 1 are placed), and are located lowerthan the lower ends of the fork mechanism 35 and the third motor M3. Thelower ends of the pair of guide members 33 are located between the upperends and the lower ends of the support portion 31, along the verticaldirection Y

The connecting portion 41, the swing portion 42, the swing mechanism 43,the sliding mechanism 44, the rotating mechanism 45, and the forkmechanism 35 are located higher than the upper ends of the supportportion 31, and the upper ends of articles 1 supported by the supportportion 31.

The rotating mechanism 45 can change the direction in which an article 1is moved by the transfer mechanism 32 by rotating the transfer mechanism32 through 180 degrees with the sixth motor M6. Therefore, even if thestorage areas E of the storage portions 3 exist on both sides, along thefront-and-back direction Z, of the vertically movable member 28 becausestorage racks 4 are installed on both sides, along the front-and-backdirection Z, of the travel path of the stacker crane 2, the transfermechanism 32 can transfer an article 1 between any of the storage areasE of storage portions 3 that exist on both sides and the support portion31.

In addition, the vertically movable member 28 includes an imaging device47 and a distance sensor 48. The imaging device 47 and the distancesensor 48 are supported by the article transfer device 30 so that theyare moved together with the fork mechanism 35 and the support portion31.

[Controller]

The stacker crane 2 includes a controller H which controls traveling ofthe travel carriage 26, vertical movements of the vertically movablemember 28, and operations of the transfer mechanism 32. This controllerH may be mounted on the stacker crane 2 so that it can move with thestacker crane 2 or may be installed on the floor surface F so that itwould not move with the stacker crane 2. Note that the controller Hcorresponds to the controller for controlling the first actuator and thesecond actuator.

The controller H performs a movement control and transfer controls. Inaddition, after the controller H completes a movement control, itperforms a correction control before starting a transfer control.

A movement control is a control for causing the vertically movablemember 28 to be moved to a target stop location. A transfer control is acontrol for causing one or more articles 1 to be moved or transferredbetween the support portion 31 and one or more storage areas E of astorage portion 3. A transfer control may be any of a double retrievalcontrol, a double storage control, a single retrieval control, and asingle storage control.

A double retrieval control is a control for causing a pair of articles 1(a pair of servers 1 s) stored in a storage portion 3 to be moved fromthe storage areas E to the support portion 31 as shown in FIGS. 14-16. Adouble storage control is a control for causing a pair of articles 1 (apair of servers 1 s) supported by the support portion 31 to be movedfrom the support portion 31 to storage areas E as shown in FIGS. 16, 17,15, and 14, in that order. A single retrieval control is a control forcausing one (one server 1 s) of the pair of the articles 1 (a pair ofservers 1 s) stored in a storage portion 3 to be moved from a storagearea E to the support portion 31, as shown in FIG. 18-FIG. 20. A singlestorage control is a control for causing one (one server 1 s) of a pairof articles 1 (a server 1 s and a dummy article 1 d) supported by thesupport portion 31 to be moved from the support portion 31 to a storagearea E, as shown in FIGS. 20, 21, 19, and 18 in that order.

A movement control, a transfer control, and a correction control aredescribed further next using an example in which the transfer targetportion is one or both of storage areas E of a storage portion 3. Notethat, the description for when a transfer target portion is thecarry-out conveyor 5 or the carry-in conveyor 6 is omitted here sincethe operation of the stacker crane 2 in such a case is identical to theoperation for which the transfer target portion is a storage areas E ofa storage portion 3.

The information that indicates target stop locations is stored in thecontroller H. The target stop locations are set with one for each of theplurality of storage portions 3 in each of the plurality of storageracks 4. A target stop location for a storage portion 3 is such a stoplocation for the vertically movable member 28 that allows transferringof an article 1 between the storage portion 3 and the support portion31. And one target stop location is set for each storage portion 3. Andin a movement control, the operations of the first motor M1 and thesecond motor M2 are controlled in order to cause the vertically movablemember 28 to be moved to a target stop location, and, when required, theoperation of the sixth motor M6 is controlled so that the storageportion 3 that is the transfer target exists in the direction in whichthe transfer mechanism 32 projects.

In a correction control, the sixth motor M6, the seventh motor M7, andthe eighth motor M8 are controlled to correct the attitude of thearticle transfer device 30 based on image information captured by theimaging device 47 and distance information obtained by the distancesensor 48.

More specifically, in a correction control, if it is determined, basedon image information captured by the imaging device 47 and distanceinformation obtained by the distance sensor 48, that the attitude of thearticle transfer device 30 deviates angularly about an axis extendingalong the front-and-back direction Z from the proper attitude for astorage portion 3, then the eighth motor M8 of the swing mechanism 43 iscontrolled such that the angular attitude about the axis along thefront-and-back direction Z matches the proper attitude.

In addition, in a correction control, if it is determined, based on theimage information captured by the imaging device 47 and the distanceinformation obtained by the distance sensor 48, that the position of thearticle transfer device 30 along the lateral direction X deviates fromthe proper position for a storage portion 3 along the lateral directionX, then the seventh motor M7 of the sliding mechanism 44 is controlledsuch that the position of the article transfer device 30 along thelateral direction X matches the proper position.

In addition, in a correction control, if it is determined, based on theimage information captured by the imaging device 47 and the distanceinformation obtained by the distance sensor 48, that the position of thearticle transfer device 30 along the vertical direction Y deviates fromthe proper position for a storage portion 3 along the vertical directionY, then the second motor M2 is controlled such that the position of thearticle transfer device 30 along the vertical direction Y matches theproper position.

A transfer control is described next.

When initiating a double retrieval control, no articles 1 are supportedby the support portion 31 whereas two servers 1 s are stored in astorage portion 3, as shown in FIG. 14. In addition, the distancebetween the pair of guide members 33 is set to be the second distance.

And, as shown in FIG. 15, in the double retrieval control, the pair ofthe fork mechanisms 35 are projected until the interlocking portions 37contact the front wall portions 10 b of the servers 1 s stored in thestorage portion 3, then the interlocking portions 37 of the pair of forkmechanisms 35 are lowered from the second height to the first height tocause the interlocking portions 37 to be interlocked with theinterlocked portions 16 of the servers 1 s and also to cause theoperating portions 38 to operate the operated portions 15 a of the lockmechanisms 13 to switch the lock mechanisms 13 from the locking state tothe lock release state. Subsequently, as shown in FIG. 16, the pair offork mechanisms 35 are retracted to a pull out position to move togetherthe two servers 1 s, stored in the storage portion 3, from the storageportion 3 to the support portion 31. Thereafter, the distance betweenthe pair of guide members 33 is changed from the second distance to thefirst distance.

When initiating a double storage control, two servers 1 s are supportedby the support portion 31 whereas no servers 1 s are stored in a storageportion 3, as shown in FIG. 16. In addition, the distance between thepair of guide members 33 is set to be the first distance.

And, as shown in FIG. 15, in the double storage control, the pair of thefork mechanisms 35 are projected until the first engaging portions 11 ofthe servers 1 s to be stored contact the first engaged portions 21, thenthe interlocking portions 37 of the pair of fork mechanisms 35 areraised from the first height to the second height to cause theinterlocking portions 37 to be released upward from the interlockedportions 16 of the servers 1 s and also to cause the operating portions38 to release the operated portions 15 a of the lock mechanisms 13 toswitch the lock mechanisms 13 from the lock release state to the lockingstate. In addition, the distance between the pair of guide members 33 ischanged to from the first distance to the second distance while the twoservers 1 s are being so moved, or more specifically, when, as shown inFIG. 17, the back end portions 9 a of the servers 1 s being moved andthe forward ends of the side walls 17 a overlap along the front-and-backdirection Z. Subsequently, as shown in FIG. 14, the pair of forkmechanisms 35 are retracted to a reference position.

When initiating a single retrieval control, one dummy article 1 d issupported by the support portion 31 whereas two servers 1 s are storedin a storage portion 3, as shown in FIG. 18. In addition, the distancebetween the pair of guide members 33 is set to be the second distance.

And, as shown in FIG. 19, in the single retrieval control, one of thefork mechanisms 35 in the pair is projected until the interlockingportion 37 contacts the front wall portion 10 b of the server 1 s storedin the storage portion 3, then the interlocking portion 37 of that forkmechanism 35 is lowered from the second height to the first height tocause the interlocking portion 37 to be interlocked with the interlockedportion 16 of the server 1 s and also to cause the operating portion 38to operate the operated portion 15 a of the lock mechanism 13 to switchthe lock mechanism 13 from the locking state to the lock release state.Subsequently, as shown in FIG. 20, one of the fork mechanisms 35 in thepair is retracted to a pull out position to move one of the two servers1 s, stored in the storage portion 3, from the storage portion 3 to thesupport portion 31. Thereafter, the distance between the pair of guidemembers 33 is changed from the second distance to the first distance.

When initiating a single storage control, a server 1 s and a dummyarticle 1 d are supported by the support portion 31 whereas one server 1s is stored in a storage portion 3, as shown in FIG. 20. In addition,the distance between the pair of guide members 33 is set to be the firstdistance.

And, as shown in FIG. 19, in the single storage control, one of the forkmechanisms 35 in the pair is projected until the first engaging portions11 of the server 1 s to be stored contact the first engaged portions 21,then the interlocking portion 37 of the one of fork mechanisms 35 in thepair is raised from the first height to the second height to cause theinterlocking portion 37 to be released upward from the interlockedportion 16 of the server 1 s and also to cause the operating portion 38to release the operated portion 15 a of the lock mechanism 13 to switchthe lock mechanism 13 from the lock release state to the locking state.In addition, the distance between the pair of guide members 33 ischanged to from the first distance to the second distance while the oneserver 1 s is being so moved, or more specifically, when, as shown inFIG. 21, the back end portion 9 a of the server 1 s being moved and theforward ends of the side walls 17 a overlap along the front-and-backdirection Z. Subsequently, as shown in FIG. 14, the one fork mechanism35 is retracted to the reference position.

As described above, the fork mechanisms 35 for guiding the interlockingportions 37 along the front-and-back direction Z and the third motors M3for moving the interlocking portions 37 along the front-and-backdirection Z are located higher than the articles 1 supported by thesupport portion 31. Thus, the portion of the vertically movable member28 that is lower than the support portion 31 can be made to have smallerdimension along the vertical direction Y. And so, as shown in FIG. 11,the vertically movable member 28 can be lowered to a height at which thelower ends of the support portion 31 are located lower than the topsurfaces of the guide rails 25.

[Alternative Embodiments]

(1) In the embodiment described above, the length of the support portionalong the front-and-back direction is shorter than the distance betweenthe pair of guide rails along the front-and-back direction; and, thesupport portion is so located to be between the pair of guide railsalong the front-and-back direction. However, the length of the supportportion along the front-and-back direction may be longer than thedistance between the pair of guide rails along the front-and-backdirection; and, the support portion may be so located to overlap withthe pair of guide rails as seen along a vertical direction.

Also, in the embodiment described above, the support portion is solocated that it does not overlap with the travel portion as seen alongthe vertical direction. However, for example, a pair of support columnsthat are spaced apart from each other along the front-and-back directionmay be installed vertically on the travel carriage with the verticallymovable member located between the support columns; so, the supportportion may be so located to overlap with the travel portion as seenalong the vertical direction.

(2) In the embodiment described above, transfer target portions arelocated on both sides, along the front-and-back direction, of themovable member at rest at a target stop location. However, transfertarget portions may be located only on one side, along thefront-and-back direction, of the movable member at rest at a target stoplocation.

(3) In the embodiment described above, an interlocking portion is causedto be interlocked with interlocked portions by lowering the interlockingportion to the first height whereas the interlocking portion is releasedfrom interlocked portions by raising the interlocking portion to thesecond height. However, how an interlocking portion is caused to beinterlocked with interlocked portions may be changed suitably.

More specifically, an arrangement may be such that an interlockingportion is caused to be interlocked with interlocked portions by raisingthe interlocking portion to an interlocking height whereas theinterlocking portion is released from interlocked portions by loweringthe interlocking portion to a release height. Alternatively, anarrangement may be such that an interlocking portion is caused to beinterlocked with, and is released from, interlocked portions by swingingthe interlocking portion about an axis extending along thefront-and-back direction.

(4) In the embodiment described above, two articles supported by thesupport portion and adjacent to each other along the lateral directionare described to form a first article group. However, a first articlegroup may be formed by three or more articles supported by the supportportion and arranged one adjacent to another along the lateraldirection. In this case, the support portion would be configured to becapable of supporting three or more articles arranged one adjacent toanother along the lateral direction.

In addition, two articles supported by a storage rack and adjacent toeach other along the lateral direction formed a second article group.However, a second group may be formed by three or more articlessupported by a storage rack and arranged one adjacent to another alongthe lateral direction. In this case, a storage portion would definethree or more storage areas arranged one adjacent to another along thelateral direction.

And, when, for example, the first group is formed by three articlessupported by the support portion and arranged one adjacent to anotheralong the lateral direction and the only article to be transferred isthe one located in the middle along the lateral direction among thesethree articles, and this one article, to be transferred, is to be movedalong the front-and-back direction by means of the transfer mechanism tomove it from the support portion to a storage area, then the transfermechanism moves the article being transferred along the front-and-backdirection by guiding one lateral side portion of the article beingtransferred with one of the first article group that is not the articlebeing transferred (the article located to one side of the article beingtransferred), and by guiding the other lateral side portion of thearticle being transferred by the other of the first article group thatis not the article being transferred (the article located to the otherside of the article being transferred).

(5) In the embodiment described above, a plurality of storage portionsare arranged one above another along the vertical direction and aplurality of storage portions are arranged one adjacent to another alongthe lateral direction. However, a plurality of storage portions arearranged one above another only along the vertical direction or onlyalong the lateral direction.

In addition, an article is either a server or a dummy article in theembodiment above. However, an article may be something different fromthese as desired, such as, a pallet for supporting a load, or acontainer for holding a load.

(6) In the embodiment described above, an interlocking portion consistsof a pair of interlocking members; however, an interlocking portion mayconsist of one interlocking member or of three or more interlockingmembers. In addition, to have the corresponding number of interlockedportion(s), an article may have only one interlocked portion, or threeor more interlocked portions. Incidentally, the number of interlockingportions may be different from the number of interlocked portions. Forexample, a plurality of interlocking portions may be interlocked withone interlocked portion.

In the embodiment described above, the interlocking portion (each of theinterlocking members of a pair) is formed to be generally flat and thinwhich extends along the vertical direction Y and along thefront-and-back direction Z. However, the shape of the interlockingportion may be changed as desired so long as it has a shape that allowsit to be interlocked with an interlocked portion. For example, theinterlocking portion may be generally formed in a shape of a circularrod.

In other words, an interlocking portion may consist of only oneinterlocking member, which may be generally formed in a shape of acircular rod that extends vertically. More specifically, an interlockingportion may be configured as follows.

As shown in FIG. 22, the interlocked portion 16 is located only in thecentral area, along the lateral direction X, of the front wall portion10 b of an article 1. The interlocking portion 37 consists of oneinterlocking member 37 a generally formed in a shape of a circular rodextending along the vertical direction Y. In addition, the interlockedportion 16 and the interlocking member 37 a are formed such that theinner dimension, along the lateral direction X, of the generallyU-shaped interlocked portion 16 is greater than the outer dimension,along the lateral direction X, of the interlocking member 37 a. And theinterlocking member 37 a is interlocked with the interlocked portion 16such that the interlocking member 37 a can move with respect to theinterlocked portion 16 along the lateral direction X.

By generally forming the interlocking member 37 a in a shape of acircular rod extending along the vertical direction Y, As shown in FIG.23, even when the interlocking portion 37 is interlocked with theinterlocked portion 16 of the article 1, it is easier for the article 1to be swung about the interlocking portion 37.

In addition, as shown in FIG. 22, the operated portion 15 a of the lockmechanism 13 of an article 1 projects from a portion of the front wallportion 10 b of the article 1 that is located to one side of the centeralong the lateral direction X. The operating portion 38 is formed to begenerally flat and thin which extends along the vertical direction Y andalong the lateral direction X. An operating portion 38 is located toeach of one and the other side, along the lateral direction, of theinterlocking member 37 a.

By providing the transfer mechanism 32 with a pair of operating portions38 as described above, the lock mechanism 13 of the article 1 can beunlocked regardless of whether the operated portion 15 a projects from aportion of the front wall portion 10 b of the article 1 that is locatedto one side of the center along the lateral direction X or to the otherside. Note that, if it can be assumed that the operated portion 15 aprojects only from a portion of the front wall portion 10 b of thearticle 1 that is located to one side of the center along the lateraldirection X, then the interlocking member 37 a can be located to onlyone side, along the lateral direction X, of the operating portion 38.

(7) In the embodiment described above, no dummy articles are stored inthe storage portions. However, dummy articles may be stored in thestorage portions. When dummy articles are stored in storage portions inplace of servers, each dummy article may be provided with interlockedportion(s), first engaging portion, second engaging portion, a lockmechanism, etc.

More specifically, as shown in FIG. 24, two dummy articles 1 d may bedesignated as the articles to be transferred; and, the pair of dummyarticle 1 d supported by the support portion 31 of the verticallymovable member 28 may be moved from the support portion 31 to storageareas E by performing a double storage control. In addition, a pair ofdummy articles 1 d stored in the storage areas E of a storage portion 3may be moved from the storage areas E to the support portion 31 througha double retrieval control.

Also, as shown in FIG. 25, one server 1 s and one dummy article 1 d maybe designated as the articles to be transferred; and, one server 1 s andone dummy article 1 d supported by the support portion 31 of thevertically movable member 28 may be moved from the support portion 31 tostorage areas E by performing a double storage control. In addition, oneserver 1 s and one dummy article 1 d stored in the storage areas E of astorage portion 3 may be moved from the storage areas E to the supportportion 31 through a double retrieval control.

Also, as shown in FIG. 26, one dummy article 1 d may be designated asthe article to be transferred; and, only one dummy article 1 d (out ofone server 1 s and one dummy article 1 d supported by the supportportion 31 of the vertically movable member 28) may be moved from thesupport portion 31 to a storage area E by performing a single storagecontrol. Also, only one dummy article 1 d (out of one server 1 s and onedummy article 1 d stored in the storage areas E of a storage portion 3)may be moved from a storage area E to the support portion 31 through asingle retrieval control.

[Summary of Embodiments Described Above]

A brief summary of the article transport apparatus described above isprovided next.

An article transport apparatus comprises: a movable member having asupport portion for supporting an article from below; and firstactuators for moving the movable member, characterized in that themovable member includes a transfer mechanism for moving an articlebetween the support portion and a transfer target portion, to or fromwhich the article is to be transferred, with the support portion andtransfer target portion in alignment with each other, wherein, with atarget stop location being a location at which the movable member isstopped when moving an article between the support portion and thetransfer target portion with the transfer mechanism, with afront-and-back direction being a direction along which the movablemember and the transfer target portion are spaced apart from each otheras seen along the vertical direction when the movable member is locatedat the target stop location, and with a lateral direction being adirection that crosses the front-and-back direction as seen along thevertical direction, the transfer mechanism includes an interlockingportion capable of being interlocked with an article along thefront-and-back direction, a first guide portion for guiding theinterlocking portion along the front-and-back direction, and a secondactuator for moving the interlocking portion along the front-and-backdirection, wherein the transfer mechanism moves an article between thesupport portion and the transfer target portion by moving theinterlocking portion along the front-and-back direction by means of thesecond actuator with the movable member located at the target stoplocation, and wherein the first guide portion and the second actuatorare located higher than an article supported by the support portion.

With such an arrangement, an article, with which the interlockingportion is interlocked, is moved between the support portion and thetransfer target portion by moving the interlocking portion along thefront-and-back direction by means of the second actuator with themovable member located at the target stop location.

And the first guide portion for guiding the interlocking portion alongthe front-and-back direction and the second actuator for moving theinterlocking portion along the front-and-back direction are locatedhigher than an article supported by the support portion. Thus, it is notnecessary to locate either the first guide portion or the secondactuator lower than the support portion. Thus a portion of the movablemember that is located lower than the support portion can be madesmaller in size along the vertical direction. Accordingly, the movablemember can be arranged, or can be lowered further, such that the supportportion can be located at a lower height, compared with a case where thefirst guide portion and the second actuator are located lower than thesupport portion, which makes it possible to transfer articles to andfrom transfer target portions at low heights.

Here, the transfer mechanism preferably further includes a thirdactuator for moving the interlocking portion to a first height at whichthe interlocking portion is interlocked with an interlocked portion ofan article, and to a second height at which the interlocking portion isreleased from the interlocked portion and is retracted upward from theinterlocked portion, wherein the third actuator is preferably locatedhigher than an article supported by the support portion.

With such an arrangement, the third actuator for moving the interlockingportion along the vertical direction is located higher than an articlesupported by the support portion, as with the first guiding portion andthe second actuator. Thus, the first guide portion for guiding theinterlocking portion along the front-and-back direction, the secondactuator for moving the interlocking portion along the front-and-backdirection, and the third actuator for moving the interlocking portionalong the vertical direction can all be located higher than an articlesupported by the support portion. This arrangement makes it easier tocouple movement of an interlocking portion along the front-and-backdirection with its movement along the vertical direction, which cansimplify the structure of the transfer mechanism.

In addition, the transfer target portions are preferably located on bothsides, along the front-and-back direction, of the movable member stoppedat the target stop location, wherein the movable member preferablyincludes a fourth actuator for rotating the transfer mechanism throughat least 180 degrees about an axis extending along a vertical direction,and wherein the fourth actuator is preferably located higher than anarticle supported by the support portion.

With such an arrangement, the direction in which an article is moved canbe switched from one sense or direction along the front-and-backdirection to the other sense or direction by rotating the transfermechanism through 180 degrees with the fourth actuator. Thus, even ifthe transfer mechanism operates to transfer an article only between atransfer target portion that is located on one side along thefront-and-back direction and the support portion, it becomes possiblefor the transfer mechanism to transfer an article between a transfertarget portion that is located on the other side along thefront-and-back direction and the support portion by rotating thetransfer mechanism through 180 degrees with the fourth actuator. Thus,while keeping the structure and arrangement of the transfer mechanismsimple, the transfer mechanism can transfer an article between thesupport portion and either of the transfer target portions on both sidesalong the front-and-back direction by rotating the transfer mechanism.

Also, a pair of guide rails extending along the lateral direction arepreferably so located to be spaced apart from each other along thefront-and-back direction, wherein the article transport apparatuspreferably further comprises: a travel portion for traveling on the pairof guide rails along the lateral direction; and a second guide portionwhich is arranged vertically on the travel portion to guide the movablemember along the vertical direction, wherein the first actuatorspreferably include a travel actuator which causes the travel portion totravel, and a vertical movement actuator for moving the movable memberalong the second guide portion along the vertical direction, and whereinthe support portion is preferably so located to be between the pair ofguide rails along the front-and-back direction and is so located thatthe support portion does not overlap with the travel portion, as seenalong a vertical direction.

With such an arrangement, the movable member is moved along the lateraldirection as the travel portion is caused to travel by the travelactuator, and is moved along the vertical direction as the movablemember is moved along the second guide portion by the vertical movementactuator. And the support portion is so located to be between the pairof guide rails along the front-and-back direction and is so located thatthe support portion does not overlap with the travel portion, as seenalong a vertical direction; so, the support portion would not come intocontact with either the pair of guide rails or the travel portion whenthe movable member is lowered. Therefore, the movable member can belowered to a lower height compared, for example, with a case where thesupport portion is so located to overlap with a guide rail or the travelportion as seen along the vertical direction.

In addition, the movable member preferably includes a third guideportion for contacting an article from a lateral side to guide thearticle along the front-and-back direction when the article is moved bythe transfer mechanism, wherein the third guide portion is preferablylocated, along a vertical direction, between the support portion on theone hand and the first guide portion and the second actuator on theother hand.

With such an arrangement, since the third guide portion is located,along a vertical direction, between the support portion on the one handand the first guide portion and the second actuator on the other hand,the first guide portion and the second actuator can be located tooverlap with the third guide portion as seen along the verticaldirection. Thus, it is easier to make the dimension of the movablemember along the lateral direction smaller compared with a case wherethese are located adjacent to one another along the lateral direction.

In addition, an article preferably has an interlocked portion, withwhich the interlocking portion is capable of being interlocked, at anend portion on a side opposite from a side, along the front-and-backdirection, on which a transfer target portion is located when thearticle is supported by the support portion, wherein the interlockingportion is preferably so formed that at least a portion thereof that iscapable of being interlocked with the interlocked portion is formed in ashape of a circular rod that extends along a vertical direction.

There are situations in which, because, for example, the transfer targetportion being at an angle with the moving direction of the interlockingportion, the direction in which the article being transferred is movedby the movement of the interlocking portion does not match with thedirection in which the article being transferred is guided within thetransfer target portion, as seen along the vertical direction. Even insuch a situation, because the interlocked portion of the article isinterlocked with a portion of the interlocking portion that is formed ina shape of a circular rod, it is easier for the article to swing aboutthe interlocking portion. And by allowing the article to swing about theinterlocking portion, it becomes easier for the article to change itsorientation to an appropriate orientation for the transfer targetportion, which makes it possible to avoid any damages to the articlewhile guided in the transfer target portion.

DESCRIPTION OF REFERENCE NUMERALS AND SYMBOLS

1 Article

1 s Server (Article)

1 d Dummy article (Article)

2 Stacker crane (Article Transport Apparatus)

25 Guide rail

26 Travel carriage (Travel portion)

27 Support Column (Second guide portion)

28 Vertically movable member (Movable member)

31 Support portion

32 Transfer mechanism

33 Guide member (Third guide portion)

35 Fork mechanism (First guide portion)

37 Interlocking portion

M1 First motor (Travel actuator, First actuator)

M2 Second motor (Vertical movement actuator, First actuator)

M3 Third motor (Second actuator)

M4 Fourth motor (Third actuator)

X Lateral direction

Y Vertical direction

Z Front-and-back direction

1. An article transport apparatus comprising: a movable member having asupport portion for supporting an article from below; and firstactuators for moving the movable member, the movable member includes atransfer mechanism for moving an article between the support portion anda transfer target portion to or from which the article is to betransferred when the support portion and transfer target portion are inalignment with each other, a target stop location is a location at whichthe movable member is stopped when moving an article between the supportportion and the transfer target portion with the transfer mechanism,front-and-back direction is a direction along which the movable memberand the transfer target portion are spaced apart from each other as seenalong the vertical direction when the movable member is located at thetarget stop location, and lateral direction is a direction that crossesthe front-and-back direction as seen along the vertical direction, thetransfer mechanism includes an interlocking portion capable of beinginterlocked with an article along the front-and-back direction, a firstguide portion for guiding the interlocking portion along thefront-and-back direction, and a second actuator for moving theinterlocking portion along the front-and-back direction, the transfermechanism moves an article between the support portion and the transfertarget portion by moving the interlocking portion along thefront-and-back direction by use of the second actuator with the movablemember located at the target stop location, and the first guide portionand the second actuator are located higher than an article supported bythe support portion.
 2. The article transport apparatus as defined inclaim 1, wherein the transfer mechanism further includes a thirdactuator for moving the interlocking portion to a first height at whichthe interlocking portion is interlocked with an interlocked portion ofan article, and to a second height at which the interlocking portion isreleased from the interlocked portion and is retracted upward from theinterlocked portion, and wherein the third actuator is located higherthan an article supported by the support portion.
 3. The articletransport apparatus as defined in claim 1, wherein the transfer targetportions are located on both sides, along the front-and-back direction,of the movable member stopped at the target stop location, wherein themovable member includes a fourth actuator for rotating the transfermechanism through at least 180 degrees about an axis extending along avertical direction, and wherein the fourth actuator is located higherthan an article supported by the support portion.
 4. The articletransport apparatus as defined in claim 1, wherein a pair of guide railsextending along the lateral direction are so located to be spaced apartfrom each other along the front-and-back direction, wherein the articletransport apparatus further comprises: a travel portion for traveling onthe pair of guide rails along the lateral direction; and a second guideportion which is arranged vertically on the travel portion to guide themovable member along the vertical direction, wherein the first actuatorsinclude a travel actuator which causes the travel portion to travel, anda vertical movement actuator for moving the movable member along thesecond guide portion along the vertical direction, and wherein thesupport portion is so located to be between the pair of guide railsalong the front-and-back direction and is so located that the supportportion does not overlap with the travel portion, as viewed along avertical direction.
 5. The article transport apparatus as defined inclaim 1, wherein the movable member includes a third guide portion forcontacting an article from a lateral side to guide the article along thefront-and-back direction when the article is moved by the transfermechanism, and wherein the third guide portion is located along avertical direction between the support portion on the one hand and thefirst guide portion and the second actuator on the other hand.
 6. Thearticle transport apparatus as defined in claim 1, wherein an articlehas an interlocked portion, with which the interlocking portion iscapable of being interlocked, at an end portion on a side opposite froma side, along the front-and-back direction, on which a transfer targetportion is located when the article is supported by the support portion,wherein the interlocking portion is so formed that at least a portionthereof that is capable of being interlocked with the interlockedportion is formed in a shape of a circular rod that extends along avertical direction.
 7. The article transport apparatus as defined inclaim 2, wherein the transfer target portions are located on both sides,along the front-and-back direction, of the movable member stopped at thetarget stop location, wherein the movable member includes a fourthactuator for rotating the transfer mechanism through at least 180degrees about an axis extending along a vertical direction, and whereinthe fourth actuator is located higher than an article supported by thesupport portion.
 8. The article transport apparatus as defined in claim2, wherein a pair of guide rails extending along the lateral directionare so located to be spaced apart from each other along thefront-and-back direction, wherein the article transport apparatusfurther comprises: a travel portion for traveling on the pair of guiderails along the lateral direction; and a second guide portion which isarranged vertically on the travel portion to guide the movable memberalong the vertical direction, wherein the first actuators include atravel actuator which causes the travel portion to travel, and avertical movement actuator for moving the movable member along thesecond guide portion along the vertical direction, and wherein thesupport portion is so located to be between the pair of guide railsalong the front-and-back direction and is so located that the supportportion does not overlap with the travel portion, as viewed along avertical direction.
 9. The article transport apparatus as defined inclaim 3, wherein a pair of guide rails extending along the lateraldirection are so located to be spaced apart from each other along thefront-and-back direction, wherein the article transport apparatusfurther comprises: a travel portion for traveling on the pair of guiderails along the lateral direction; and a second guide portion which isarranged vertically on the travel portion to guide the movable memberalong the vertical direction, wherein the first actuators include atravel actuator which causes the travel portion to travel, and avertical movement actuator for moving the movable member along thesecond guide portion along the vertical direction, and wherein thesupport portion is so located to be between the pair of guide railsalong the front-and-back direction and is so located that the supportportion does not overlap with the travel portion, as viewed along avertical direction.
 10. The article transport apparatus as defined inclaim 2, wherein the movable member includes a third guide portion forcontacting an article from a lateral side to guide the article along thefront-and-back direction when the article is moved by the transfermechanism, and wherein the third guide portion is located along avertical direction between the support portion on the one hand and thefirst guide portion and the second actuator on the other hand.
 11. Thearticle transport apparatus as defined in claim 3, wherein the movablemember includes a third guide portion for contacting an article from alateral side to guide the article along the front-and-back directionwhen the article is moved by the transfer mechanism, and wherein thethird guide portion is located along a vertical direction between thesupport portion on the one hand and the first guide portion and thesecond actuator on the other hand.
 12. The article transport apparatusas defined in claim 4, wherein the movable member includes a third guideportion for contacting an article from a lateral side to guide thearticle along the front-and-back direction when the article is moved bythe transfer mechanism, and wherein the third guide portion is locatedalong a vertical direction between the support portion on the one handand the first guide portion and the second actuator on the other hand.13. The article transport apparatus as defined in claim 2, wherein anarticle has an interlocked portion, with which the interlocking portionis capable of being interlocked, at an end portion on a side oppositefrom a side, along the front-and-back direction, on which a transfertarget portion is located when the article is supported by the supportportion, wherein the interlocking portion is so formed that at least aportion thereof that is capable of being interlocked with theinterlocked portion is formed in a shape of a circular rod that extendsalong a vertical direction.
 14. The article transport apparatus asdefined in claim 3, wherein an article has an interlocked portion, withwhich the interlocking portion is capable of being interlocked, at anend portion on a side opposite from a side, along the front-and-backdirection, on which a transfer target portion is located when thearticle is supported by the support portion, wherein the interlockingportion is so formed that at least a portion thereof that is capable ofbeing interlocked with the interlocked portion is formed in a shape of acircular rod that extends along a vertical direction.
 15. The articletransport apparatus as defined in claim 4, wherein an article has aninterlocked portion, with which the interlocking portion is capable ofbeing interlocked, at an end portion on a side opposite from a side,along the front-and-back direction, on which a transfer target portionis located when the article is supported by the support portion, whereinthe interlocking portion is so formed that at least a portion thereofthat is capable of being interlocked with the interlocked portion isformed in a shape of a circular rod that extends along a verticaldirection.
 16. The article transport apparatus as defined in claim 5,wherein an article has an interlocked portion, with which theinterlocking portion is capable of being interlocked, at an end portionon a side opposite from a side, along the front-and-back direction, onwhich a transfer target portion is located when the article is supportedby the support portion, wherein the interlocking portion is so formedthat at least a portion thereof that is capable of being interlockedwith the interlocked portion is formed in a shape of a circular rod thatextends along a vertical direction.